1. Field of the Invention
The invention relates to an apparatus for distilling liquids in a vacuum.
2. Description of the Related Art
In practice an apparatus of this kind is known which is generally referred to as rotation evaporator and is provided for use in laboratories. The receptacle of this rotation evaporator is formed as a distilling flask of glass which is rotated about its axis by means of a motor during distillation and is connected via the so-called distillation head to the condenser e.g. a product condenser such as the Liebig condenser. The so-called receiver adapter forms the connection between the condenser and the collecting vessel, the so-called receiver. The vacuum source, for example a water jet pump, is connected to the condenser in the bottom region thereof. As a heating arrangement a so-called heating bath is used, preferably having a liquid heat transfer medium that can be heated by means of an immersion heater, a gas burner or electric hot plate.
Setting up the rotation evaporator, i.e. filling the distilling flask with the liquid to be distilled, and connecting it to the receiver adapter, is time consuming and impractical, and care must be taken in particular in relation to the precision of the connecting parts, i.e. of the ground glass joint, and in careful lubrication of the latter with vacuum grease. The distilling flasks often break during distillation, as they are made of glass, so that the distillation process has to be repeated. The comparatively great inertia of the different liquid heat transfer mediums used in the heating bath allows on the one hand an appropriately accurate temperature setting, but on the other hand it requires a relatively long time for different temperatures to be set. Moreover the rotation evaporator is not suitable for carrying out continuous distillation processes.